The invention lies in the telecommunications field. Specifically, the invention pertains to a method with which performance features are provided to mobile subscribers in a communications network.
Working conditions are becoming increasingly flexible in terms of time and location. The number of employees who do not carry out their professional tasks at a fixed workplace at a company office is rising continuously. The publication xe2x80x9cDas virtuelle Bxc3xcroxe2x80x9d telcomreport, Issue 4, 1997, Siemens AG, Berlin and Munich described that for tasks to be carried out effectively outside the company building it is often necessary to have access to the communications performance features provided within the company""s local communications network. These features should be available irrespective of the location of the employee. Such performance features include the availability of a conference call setup with a conference circuit or signaling of an inputting of a message, which are additional to the standard performance features provided in a, say, ISDN-oriented communications network.
In order to enable the performance features which are implemented by a communications system to be made available at an external terminal in the same way as at an internal terminalxe2x80x94as envisioned within the scope of the so-called xe2x80x9cteleworkingxe2x80x9dxe2x80x94the commonly assigned earlier patent application Ser. No. 09/259,637 proposes that terminal-oriented signaling information, such as is usually transferred within the scope of a signaling protocol between the communications system and internal terminals which are connected to it, should be transferred between the communications system and the external terminal via a data link which is set up in addition to the user data link.
This requires two user data links to be made available at the external terminal in order to transfer the user data via a first user data link (for example a first ISDN-oriented B channel) and the terminal-oriented signaling information via a second user data link (for example a second ISDN-oriented B channel). Furthermore, it is necessary for the external terminal to be designed in such a way that the terminal-oriented signaling information which has been transferred can be evaluated.
In order to be able to make the performance features implemented by the communications system available at an external terminal, in particular a mobile terminal, our commonly assigned earlier patent application Ser. No. 09/259,915 proposed, furthermore, to transfer terminal-oriented signaling information items to the communications system via a voice link from the external mobile terminal, and vice versa, in the form of DTMF signals (Dual Tone Multi Frequency) in accordance with the MFM dialing method (Multi-Frequency dialing Method). For the DTMF signals, each key of a terminal is assigned a characteristic signal which is transferred via the voice link when the keys are operated. The DTMF signals differ in frequency and signal duration from the data normally transferred via the voice link, with the result that the DTMF signals can be identified and evaluated in the communications system.
However, this presupposes that the communications subscriber assigned to the external terminal knows the key combinations necessary for activating the performance features, and these combinations are in part long and unusual. On the other hand, the activation of a performance feature by tapping an acoustic user interface made available at the terminal by the communications system requires an unnecessarily long time interval.
It is accordingly an object of the invention to provide a method with which it is possible to render performance features otherwise available at internal subscriber terminating lines in a communications system to an external terminal, which overcomes the above-mentioned disadvantages of the heretofore-known devices and methods of this general type and which is easier to use and simpler in its application.
With the foregoing and other objects in view there is provided, in accordance with the invention, a method of providing performance features of a communications system available at internal subscriber terminating lines in the communications system to an external terminal via a communications network, which comprises:
setting up a short message service link between an external terminal and a teleworking computer connected via a teleworking subscriber line module of a communications system by signing on the external terminal with the communications system;
transferring items of control information entered at the external terminal in short message format via the short message service link to the teleworking computer; and converting the short messages received by the teleworking computer into terminal-orientated signaling information items, as are usually available according to a signaling protocol between internal terminals and the communications system, and transferring the converted short message to a control unit of the communications system via the teleworking subscriber line module.
For the purpose of a better understanding of the mode of operation of the xe2x80x9cshort message service,xe2x80x9d a brief review of these principles appears in order:
A short message service SMS (Short Message Service) for mobile communications systems has become known heretofore from the book entitled xe2x80x9cMobilfunk und Intelligente Netzexe2x80x94Grundlagen und Realisierung mobiler Kommunikationxe2x80x9d [xe2x80x9cMobile Telephony and Intelligent Networksxe2x80x94Principles and Implementation of Mobile Communicationxe2x80x9d], Friedr. Vieweg and Sohn Verlagsgesellschaft, Braunschweig/Wiesbaden, Germany, 1995 (cf. pp. 145-46). The conventional short message service SMS is used to realize bidirectional transfer of information between a so-called service centerxe2x80x94frequently denoted in the literature by xe2x80x9cSMS centerxe2x80x9dxe2x80x94and the mobile terminal assigned to the service center. Within the scope of the so-called PtP service (Point-to-Point service) information items up to a length of 160 characters can be transmitted between the service center and a mobile terminal. The information is transferred via the signaling channels available within the scope of a mobile link between the service center and the mobile terminal. It is thereby possible to transfer this information while simultaneously transferring voice data which are to be transferred between the service center and the mobile terminal within the scope of an already existing voice link.
A substantial advantage of the invention consists in that the requirements made of the external terminal consist only in supporting a short message service (SMS) by the external terminal.
In accordance with an added feature of the invention, the teleworking computer is connected to the communications system via a digital interface of a subscriber line module, and the the short message service link is routed via the subscriber line module.
In accordance with an additional feature of the invention, the teleworking computer is connected via a modem to an analog interface of a subscriber line module of the communications system, and the short message service link is routed via the subscriber line module.
In accordance with another feature of the invention, the teleworking computer is connected to the communications network via a digital interface, and to the short message service link is routed via the digital interface.
In accordance with a further feature of the invention, the short message service link is routed via a short message service unit connected to the communications network, and the short messages are transferred bidirectionally via a radio link between the short message service unit and the external terminal within a scope of the short message service link.
In accordance with again an added feature of the invention, the bidirectional transfer of the short messages is implemented via a radio link between the external terminal and the teleworking computer within the scope of the short message service link.
In accordance with again an additional feature of the invention, a sign-on authorization is checked with the teleworking computer based on subscriber-related data transferred from the external terminal via the short message service link.
In accordance with again another feature of the invention, during sign-on, the teleworking computer assigns a first virtual subscriber connection port of the teleworking subscriber line module to the external terminal, and data routed by the control unit to an internal subscriber terminating line and identified by the subscriber-specific data, are rerouted to the virtual subscriber connection port.
In accordance with again a further feature of the invention, during a connection set-up between the external terminal and a further terminal brought about subsequently to sign-on of the external terminal, a terminal link between the external terminal and the further terminal is routed via the teleworking subscriber line module.
In accordance with yet an added feature of the invention, the items of control information to be transferred from the external terminal are transferred to the communications system when the terminal link exists between the external terminal and the communications system in the short message format via the short message service link.
In accordance with yet another feature of the invention, a plurality of terminal links are simultaneously routed in each case between one external terminal signed on to the communications system and one further terminal via the teleworking subscriber line module.
In accordance with a concomitant feature of the invention, the internal subscriber terminating line is set up merely as a virtual connection port.
A particular advantage of the above-mentioned refined features of the invention is that a subscriber who has signed on to the communications system at an external terminal can be accessed on the same call number, as at an internal terminal assigned to him.
By assigning virtual connection portsxe2x80x94often referred to as pseudo-connection ports in the literaturexe2x80x94subscribers can utilize the performance features of the communications system at an external terminal even if they do not have a physically existing internal terminal assigned to them.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a method for providing performance features for mobile subscribers via a communications network, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.